I just checked out the site.
It looks like you need to be registered to download the file. I haven't gone through the registration process as I can't read Chinese, so I'll see if I can some help, unless another member here who can speak Chinese can help you register and download it for you?
After registering, I could download only 1 file and then I got the message "Your M less than 5 coin, not download attachments!". Anyway, I think this forum requires posts for coins.
I've tried to search en.s1mp3.net but I could not find the firmware. It seems that the name of the board is G-18A-Main-V0.3 and there are no firmware for that board on s1mp3...